1. Field of the Invention
The present invention is related to transport streams. In particular, the present invention is related to enhancing interface to transport streams.
2. Description of Related Art
Modern set-top boxes generally have a receiver to receive program data, or content, from a service provider and generate multiple transport streams. The content is normally scrambled before being transmitted to the receiver. The scrambled content is then de-scrambled by a conditional access (CA) device. Currently, entitlement management messages (EMM) typically use unique keys or signatures to deliver a group key or access parameters to CA devices. An EMM is a message used to deliver privileges (e.g., rights, keys) to a CA device. Typically the group are users or customers who share a particular set of entitlements.
The multiple transport streams are received by CA devices at several points of deployment (PODs). The architecture of the interface to the transport streams at the PODs defines how the transport streams are transferred and processed. An example of such an interface definition is the NRSS-B interface. The National Renewable Security System (NRSS)-B interface is characterized by pin assignments at the connector. The interface makes wasteful use of pins by sending and returning only one transport stream from the host to the CA module in parallel byte mode.
In picture-in-picture (PiP) systems, there are multiple transport streams corresponding to multiple picture sources. To accommodate multiple transport streams in PiP applications, multiple CA devices have to be used. This results in wasteful hardware resources and increases costs.
Therefore, there is a need to have an efficient technique to enhance the interface to the transport streams.